POS1344 CLINICAL AND HISTOLOGICAL FEATURES OF RESIDUAL PAIN IN RHEUMATOID ARTHRITIS REMISSION STATUS
Authors: S. Perniola, L. Petricca, M. Gessi, M. R. Gigante, M. Calabretta, D. Bruno, A. Capacci, C. Di Mario, B. Tolusso, S. Alivernini, E. Gremese
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Rheumatoid arthritis (RA) is a chronic disease characterized by a high degree of disability and pain. Remission is the optimal goal but, even when it is reached, the pain can persist as "residual pain". <h3>Objectives</h3> The aims of the study were (i) to characterize the size and perception of residual pain and (ii) to evaluate the possible impact of residual synovitis on pain perception in remission RA patients. <h3>Methods</h3> One hundred twenty-seven RA patients (defined by 2010 ACR/EULAR criteria), of which 68 in clinical and ultrasound remission (REM-RA) and 29 in high disease activity (HDA-RA) defined by DAS28-CRP were enrolled in the study. Thirty fibromyalgia patients (2016 ACR criteria) were enrolled as a control group (FIBRO). Upon enrolled, demographic, clinical and ultrasound features were collected for each patient and an assessment of pain symptom was performed for each patient according to the RAID, FACIT, GHQ and VAS-pain questionnaires. Patients with RA underwent minimally invasive ultrasound-guided biopsy of the synovial membrane of the knee in order to assess the degree of synovitis, according to the Krenn Score (KSS). <h3>Results</h3> Considering the RA group, the synovitis degree is directly correlated with the life quality and disability, as demonstrated by the inverse correlation between FACIT and DAS28-CRP (R2=-0.506, p&lt;0.0001). Furthermore, considering the pain mental aspects, the total GHQ score (R2=0.407; p&lt;0.0001) and the VAS-pain scale (R2=0.402, p&lt;0.0001) are instead directly correlated to the DAS28-CRP in RA patients. Since GHQ value ≥24 identifies a subject requiring psychiatric attention, a higher score was found in 26% of REM-RA patients compared to 52% (p=0.004) and 77% (p&lt;0.0001) in the HDA-RA and FIBRO groups respectively while, considering the VAS-pain, the REM-RA patients had lower values (20) compared to HDA-RA (50; p&lt;0.0333) and FIBRO (70; p&lt;0.0001), suggesting how the underlying pathology could affect psychological well-being and pain perception. Further confirmation was obtained with the RAID questionnaire: REM-RA patients presented lower scores (3.34) than HDA-RA (5.56; p = 0.0003) and FIBRO patients (7.63; p &lt;0.0001). Finally, considering the synovitis degree, the presence of subclinical synovitis (KSS≥2) in REM-RA patients (50%) was not associated with a higher pain score, assessed by VAS-pain, suggesting the possible non-inflammatory nature of residual pain. <h3>Conclusion</h3> Remission status in RA is associated with a better psycho-physical state than in HDA patients but, despite that, there is the persistence of a certain degree of residual pain, regardless of the subclinical synovitis degree. It emerges that the features of pain in patients in remission is different from other conditions (high disease activity or fibromyalgia), suggesting different underlying biological mechanisms. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Simone Perniola Speakers bureau: ABBVIE, ELI LILLY ITALIA, GALAPAGOS BIOPHARMA, PFIZER, NOVARTIS, Consultant of: ABBVIE, ELI LILLY ITALIA, GALAPAGOS BIOPHARMA, Luca Petricca: None declared, Marco Gessi: None declared, Maria Rita Gigante: None declared, Martina Calabretta: None declared, Dario Bruno: None declared, Annunziata Capacci: None declared, Clara Di Mario: None declared, Barbara Tolusso: None declared, Stefano Alivernini Speakers bureau: ABBVIE, ELI LILLY ITALIA, PFIZER, NOVARTIS, Consultant of: ABBVIE, ELI LILLY ITALIA, PFIZER, NOVARTIS, Grant/research support from: PFIZER, Elisa Gremese Speakers bureau: ABBVIE, ELI LILLY ITALIA, GALAPAGOS BIOPHARMA, PFIZER, NOVARTIS, Consultant of: ABBVIE, ELI LILLY ITALIA, PFIZER, NOVARTIS, Grant/research support from: ABBVIE, PFIZER, NOVARTIS.